luvsgrtdanes, I had trouble with cleome too. And then I read somewhere that the seeds like a daytime/nightime temperature fluctuation. They recommended putting them in the fridge for 12 hours and then in warm household temps (70s, I guess) and alternating that for a few days. I did this in a damp paper towel and it worked.
I'm trying a few in a container on the patio now that our daytime/nighttime temps are similar to that.